In recent years, electronic materials, such as semiconductors and LEDs, have become more compact and finer with the trend toward higher integration. In particular, there has been a strong demand for techniques of producing nanometer-scale patterns, which are finer than micrometer-scale patterns.
There are various methods for producing fine patterns, and etching using masks has been most commonly used. Of etching techniques, dry etching is often used to form highly fine patterns because of its high etching precision.
In order to increase the reproducibility of patterns to be transferred and the etching rate, resists to be used need to have high dry-etching resistance. For example, in NPL 1, it is disclosed that dry etching performance varies depending on the ratio between the number of carbon atoms and the number of other atoms, which is called the Ohnishi parameter, and examples of resins providing high dry etching performance include polystyrene. However, polystyrene has good dry-etching resistance but has no curability and hence it has been difficult to form highly fine patterns with polystyrene.
Curable compositions including a compound having a (meth)acryloyl group have been often used as a resist with which highly fine patterns can be formed. Curable compositions including a compound having a (meth)acryloyl group provide good pattern formability but have a problem of low dry etching performance because such curable compositions contain oxygen in the molecule thereof.